Automatic profile cutting machine



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AUTOMATIC PROFILE CUTTING MACHINE .8 Sheets-Sheet 2 Filed Nov. 1, 1945 INVENTORs Q. BUCKL5 6E mtaysxy O, 772/5:

flrraz/vzy Dec. 26, 1950 J. Q. BUCKLES ETAL AUTOMATIC PROFILE cu'r'rme MACHINE 8 Sheets-Sheet 4 Filed Nov. 1, 1945 r SME mm; 5 mi w n 0 Wm W wwfl E? Nam 3W aw Y B Z 2 Dec. 26, 1950 J. Q. BUCKLES ETAL AUTOMATIC PROFILE CUTTING momma Filed Nov. 1. 1945 8 Sheejzs-Sheet 5 teseur 6 r 5K5 v. 55 5 fifiw m mc zW 0 ai WPZW 0 05 6H Mf gm Je Y B Q m 0 Z Dec. 26, 1950 J. Q. BUCKLES EIAL 2,535,895

AUTOMATIC PROFILE cu'r'rmc MACHINE Filed Nov. 1, 1945 8 Sheets-Sheet 6 53 .y 5 wii 7 a? A m 6H W L a x i 2w a- A m C V 0.4m a v G B .m 0 4 G m w -1 i. i 4 l a 5.33 a M w L. a a a flag/d??? 9/ k 0 Dec. 26, 1950 J. Q. BUCKLES ETAL 2,535,895

AUTOMATIC PROFILE CUTTING MACHINE Filed Nov. 1, 1945 8 Sheets-Sheet 7 iih our

: ly. 11 I INVENTORS' (616 1V0 JOHN a. BUG/(L [6 Mfr 607257 a Dec. 26, 1950 J. 0; BUCKLES El AL AUTOMATIC momma currmc momma Filed Nov. 1, 1945 Patented Dec. 26, 1950 AUTOMATIC PROFILE; CUTTING MACHINE John Q. Buckles, George A. Lenaky, and Winthrop Trible, Cincinnati, Ohio, minors to The Cincinnati Milling Machine 00., Cincinnati, Ohio,

a corporation of Ohio Application November 1, 1945, Serial No. 625,988

25 Claims. (01. sac-13.5)

This invention relates to machine tools and more particularly to automatic pattern controlled milling machines.

One of the objects of this invention is to provide a machine for automatically progressively producing profile surfaces on each side of a work piece from a pattern or master.

Another object is to provide a pattern controlled milling machine for successively producing a series of profile surfaces on one side of a work piece, rotate the work to a new position, and successively produce a series of profile surfaces on the other side of the work piece.

Another object is to (provide an automatic pattern controlled airplane cylinder head fin milling machine.

Still another object of this invention is to provide an improved automatic pattern controlled milling machine for successively machining a series of non-contiguous profile surfaces on each side of a plurality of work pieces in one continuous automatic cycle.

And a still further object is to provide an improved combined electric and hydraulic operating and control circuit for a pattern controlled profile milling machine.

Other objects and advantages of the present invention should be readily apparent by reference to the following specification, considered in conjunction with the accompanying drawings forming a part thereof and it is to be understood that any modifications may be made in the exact structural details there shown and described, within the scope of the appended claims, without departing from or exceeding the spirit of the invention. 7

Throughout the several views of the drawings similar reference characters are employed to denote the same or similar parts.

Figure 1 is a front view of a multiple spindle pattern controlled milling machine incorporating the features of this invention.

Figure 2 is a left hand end elevation of the machine shown in Figure 1.

Figure 3 is a fragmentary sectional view on the line 3-3 of Figure 5.

Figure 4 is an enlarged fragmentary section on the line 4-4 of Figure 1.

Figure 4A is section on the line 4A4A of Figure 1.

Figure 5 is an enlarged fragmentary sectional view of a portion of the work table and pattern table indexing mechanism on the line 5-4 of Figures 2 and 6.

Figure 6 is a view partly in section on the line 33 of Figure 5.

Figure 7 is a diagrammatic view, indicated by the lines 1-4 in Figure 4, showing the relationship of work piece, pattern, cutter, and tracer during the machining of the profile portions on one side of the work piece.

Figure 8 is a perspective three-dimensional diagram showing the path of relative travel of the cutters and work during the machining of the portions on one side of the work piece.

Figure 9 is a diagrammatic view similar to Figure 7 but showing the relationship of work piece, pattern, cutter, and tracer during the machining of the profile portions onthe other side of the work piece.

Figure 10 is a perspective three-dimensional diagram similar to Figure 8 but showing the path of relative travel of the cutters and work during the machining of the portions on the side of the work piece shown in Figure 9.

Figure 11 is an elementary wiring diagram of plane cylinder heads to form the desired heat radiating fins.

Work table Such a machine comprises a base 23, Figure 1, having longitudinally extending guideways 2| upon which a work table 22 is reciprocated by a hydraulic motor comprising a hydraulic cylinder 23, Figures 4 and 12, fixed to the surface 20a of the base 20 and a contained piston 2!, connected by a piston rod 25 to an integral boss 26 of the work table 22.

Work and pattern spindles On the work table 22 is provided a series of work fixtures F having bases 21 and a pattern fixture P having base 28. Each of these fixtures is rotatably journaled, Figures 4 and 5, on the bearing surfaces 29 and 30 formed in the subsupport 8| fixed to the work table 22 by appropriate screws 32. These fixtures may be oscillated or indexed by means of an appropriate hydraulically actuated plunger 33, Figure 6, slidable in a cylinder bore 34 formed in the support 3|. Each of the plungers 33 is provided with a rack 35 engaging a gear 36 formed integral with a depending center guide spindle 3i rigidly attached to the platens 2? and it by suitable bolts 38. Thus, by applying fluid pressure to one side or the other of the plungers 33, the platens 21 and 28 may be indexed on their hearing supports 29 and 30.

Means are provided for accurately limiting the amount of index comprising a pair of abutment blocks 39 and 40 rigidly fixed to the support at by suitable screws 4|. These blocks have abutment surfaces 39a and 40a respectively engageable by a mating abutment surface 43 of a dog it, Figures 3 and 6, attached to the fixtures by suitable screws 45, upon rotation of the fixture in one direction and by an abutment surface M or iii the dog upon rotation of the fixture in the opposite direction. Thus, actuation of the plungers 33 may oscillate or index the work and pattern fixtures through 180 degrees of rotation.

Cross slide Tool spindle carrier On appropriate vertically disposed guideways 54, Figure 4, formed on the front lace oi the cross slide 49 is mounted the tool spindle carrier 55 which is reciprocated vertically by means of a hydraulic cylinder 56, which is rigidly mounted on the cross slide 49 and 9. contained piston 51 which is attached by a piston rod 58 to an integral lug 59 of the spindle carrier 55. Thus, upon application of fluid pressure to the cylinder 5 the spindle carrier 43 may be raised or lowered on the guideways 54.

The spindle carrier 55 comprises a horizontally elongated housing portion upon which is fixed a series of spindle brackets 80 in which are ,iournaled the cutter spindles 6i. Each cutter spindle carries a cutter arbor 62 upon which is mound ed a thin milling or slotting cutter 65. Each pair of spindles 6| is driven by a motor it mounted on the spindle carrier 55 and connected through motor pulleys 65 and belts 66 to appropriate pul= leys 61 carried by the respective spindles dfl so that the spindles may be rotated at the deshed cutting speed for any vertical position oi the spindle carrier.

Also carried by the spindle carrier is the tracer support bracket it upon which is moun ed the tracer control valve til having a pattern con= tacting disc or tracer it which is of the same diameter as the cutter 633. This tracer disc id is arranged to engage a series of patterns or tern plates comprising a pattern array P mounted rigidly on the platen it as best seen l and 4. I

General operating cycle in this particular exemplary disclosure, the work piece comprises an airplane cylinder head W having a main cylindrical body portion on each sideof which are to be cut a group or series oi slots to form heat radiating fins, one series being of diiferent configuration or depth than the other. On one side oi the worir W is a group of slots A to be machined to the general corn figuration shown by the cross hatch portion merited A Figure t. On the other side of the work is a group oi slots B to be machined to the general configuration of the cross hatch portion indicated at B in Figure 9. In Figures 7 and 9 the pattern or template is shown superimposed in the same relative position upon the work piece to illustrate the relationship of the template and the slots to be out. There is also shown in these figures a series of circles TC which represent the diameter of both the cutter and the tracer to show the relative positions'of these members with relation to the work and template at different stages of the machining cycle.

The template array P is mounted on the platen 28 and the work pieces W are gripped in appropriate work fixtures F on the platens 21 in such a way that they assume the position shown in Figure 7 at the beginning of the cutting cycle. At this time the dog 44, Figures 3 and 6, on the fixtures will be in engagement with the face 39a on the abutment block 39.

For simplicity of illustration, in Figures 7 and 9, the work and pattern fixtures are assumed fixed while the cutters and tracer disc are moved relative to them to their various operating positions as occur in the machining cycle. At the beginning of the machining cycle the cross slide is fully retracted, putting the tracer and cutters in position II and the fixtures are to the right of axis 12 whereby the table 22 is in a position to feed to the left. The cross slide moves forward first at rapid traverse and then at a decreasing iced rate moving the tracer disc 10 from H to I4 into engagement with the template surface It. This arrests further inward movement of the cross slide and establishes the tracer in control of the cross slide.

- The work table 22 then starts feeding as indinoted by the arrow 15 causing the tracer to follow the irregular profile surface 13a and the cutters to machine the first slot in group A in the work. The cutters and tracer ultimately arrive at the position 16, Figures 7 and 8, to thereby complete the profile milling of the first slot in group A.

I At position II the table feeding movement stops and the cross slide moves the cutters and tracer back to the position TI. At this position the spindle carrier is moved or indexed upwardly a scient amount to position Ila, Figure 8, to bring the cutters and tracer disc into proper client i'or cutting the next successive slot in pinup A.

'1 At the completion of the indexing at position lls the work table 22 returns at rapid traverse shown by the arrow 15a, thereby relatively positioning cutter and tracer disc at 18 in Figures if and 8. The work table 22 stops and the cross slide advances again to move the cutter and tracer from position it to position 14. The cycle or cutting the next slot repeats.

At the completion of the machining of th s next slot, the cross slide again withdraws to pceition ll where again upward indexing to position lib, Figure e, takes place for machining the slot. The table at, rapid traverse returns to position i! and this cycle of operation continues until all of the slots have been progressively machined in group A.

at the completion of the machining of the last slot in group A with the cutters in the poeition it, the cross slide is caused to fully withdraw to position it, Figure '7, but during the withdrawal at position H the spindle carrier is moved downwardly, to return the cutters and tracer to the starting plane. With the cutters and tracer at position I8 the fixtures are indexed clockwise 180 degrees, Figure 7, to present the other side of the work for slotting. The work table 22 then rapid returns to bring the cutters and tracer to the position 88 in Figure 9, whereupon the cross slide advances to position the cutters and tracer at 8| with tracer disc engaging the surface 82 of the first template of group B to thereby establish tracer control of the cross slide movement. The work table then feeds in the direction b with the tracer following the irregular profile surface 82a of the first template of group B. The table 22 stops at position 84, and the cross slide withdraws the cutters and tracer to position 85. At this position the spindle carrier indexes up a sufflcient distance to present the cutter and tracer to position 85a to cut the next succeeding slot of group B. The work table 22 then rapid returns as indicated by the arrow 150 to bring the cutters and tracer to the position 88. The cross slide then advances to repeat the cycle and cut the next slot in the work.

After all the slots have been cut in group B, the cross slide withdraws to the fully retracted position 81, the downward return movement of the spindle carrier also taking place at position 85. When point 81 is reached the fixtures are indexed counterclockwise 188 degrees, Figure 9, and the work table 22 rapid returns to bring the cutter and tracer disc into the starting position II, Figure '7, for unloading the completed work.

Hydraulic operating system The work table, fixtures, cross slide, and spindle carrier are hydraulically operated and controlled by a hydraulic control circuit shown diagrammatically in Figure 12. Referring to this figure, fluid pressure for reciprocating the work table is derived from a main pump 88 which withdraws fluid through suction line 88 from reservoir 88 and delivers it under pressure to line 8I which is connected through a branch line 8Ia to the pilot operated table feed and rapid traverse control valve 82. This control valve has a hydraulically shiftable plunger 88 and is provided at each end with pressure chambers 84 and 85 in which are centralizing bushings 88 and 81 which are effective to locate the plunger 83 in an intermediate position when the pressure is simultaneously applied to both chambers 84 and 85.

Fluid pressure for the pressure chambers 84 and 85 is supplied from an auxiliary pump 88 which withdraws fluid through a suction line 88 from the reservoir 88 and delivers it under pressure through line I88 and branch line I88a to the table .pilot control valve I8I. This valve has a plunger 182 which is normally centered by appropriate compression springs I83 located at each end of the plunger and is actuated in one direction or the other by electrical solenoids I84 and I85 connected to it by an appropriate bell crank operating lever I88. The solenoids are part of an electrical circuit shown in Figure 11 to be described later.

The feeding direction of movement of the work table 22 is instituted by a dog 218 on the cross slide 48 causing energization of the solenoid I84 when the cross slide has completed its advance so as to shift the valve plunger I82 in pilot valve IM to the left, thus connecting pressure from line I880 through the annular groove I81 of the plunger I82 to the line I88 leading to the pressure chamber of valve 82 so as to shift the plunger 83 to the right. Fluid is discharged from chamber 84 through line I88, annular groove H8 of valve plunger I82 to the drain line III for return to the reservoir 88. Shifting of the plunger 88 connects pressure from line 8la through annular groove I I2 and line M3 to the chamber II4 of the table actuating cylinder 23 whereby the piston 24 feeds the work table 22 to the left.

Fluid is discharged from the other end of chamber II5 of the cylinder 23 through line IIS, branch line IISc, to a feed approach throttle valve 1. This valve has a plunger I28' and a pressure chamber H8 in one end adapted to receive fluid from the line II6c through groove I21 and an interdrilled passageway H8 in valve plunger I28 whereby the fluid pressure continuously urges the plunger against a compression spring I2I provided in the other end of the valve. A line I22 is connected to an auxiliary control valve I28 having a plunger I24 which is actuated by a cam I 25 carried by the work table 22in such a way as to control axial movement of the plunger by a spring I23a and open the discharge from line I22 into line I28 and thereby change the pressure in chamber 8 of the valve III to increase the rate of discharge of fluid through the line IIBc, causing the table to increase its rate of movement.

Thus, as the table begins to move forward, the valve plunger I24 begins to,.ride down on the tapered surface I28 of the cam I25, causing feed rate to increase as the table feed movement gets under way. The purpose of this arrangement is to initially feed the cutters into the work gradually and then increase the feed as the full depth of the cutters becomes effective.

The rate of movement of the work table 22 is also subject to variation by the tracer valve 88. This valve has a valve plunger I28 urged in one direction by a spring 28I and in the other direction by the pattern acting on the tracer disc I8. This plunger has an annular groove I38 which when the plunger is in a central neutral tracing position interconnects port I3I to port I3Ia, each port being half-way open. This is the maximum flow position for fluid coming through line I28 from the feed rate control valve I23 and passing out through port I3Ia into line I32. Line I32 is connected through the annular groove I33 of the valve plunger 83 of the table control valve 82 to the drain line III. With this arrangement changes of contour in the pattern during the tracing operation will shift the valve plunger I28 to one side or the other of its control position, but regardless of which direction it is shifted, it will reduce the rate of flow through the valve and thereby reduce the feed rate of the table.

When the table reaches the end of its feeding stroke a dog on the table operates on the electrical circuit to deenergize solenoid I84, whereby the springs I83 automatically centralize the valve I82, thereby causing centralization of the table control valve 82 through the hydraulic connection described, thus stopping the table. The table remains stationary until the spindle carrier is retracted and indexed to its next upper position. A dog on the spindle carrier then operates on the electrical control circuit to energize solenoid I85 which shifts pilot valve plunger I82 to the right as viewed in Figure 12.

This connects fluid pressure from the line I88a through the annular groove I81, line I88 to chain.

ber 34. thereby moving plunger 33 to the left. Discharge fluid from opposite chamber 33 flows through line I03, annular groove I34a of the valve plunger I02 into the drain line III for return to reservoir 33. This connects the pump 33 through the lines 3i and 3m, annular groove II2, line H341 to line 6, and also connects the auxiliary pump 33 through lines I and "lb, annular groove 133a in plunger 03, and line I I3b to the line I I3 so that both pumps now are supplying fluid pressure at large volume to the chamber I I of the table cylinder 23 to effect a rapid return of the work table. At this time, fluid is being discharged from the chamber II4 through the line II3, annular groove I33 of the valve plunger 33 of the valve 32 into the drain line III for return to the reservoir 30. When the return movement is completed the solenoid I05 is deenergized, and the table valve 32 is again centralized in its stop position.

The indexing of the fixtures 21 and 23 in one direction or the other through 180 degrees to present either group A or B into cutting position is controlled by the spindle indexing control valve I34 having a plunger I35 which may be actuated by hydraulic pressure applied in the pressure chambers I33 and I31. when the slots of group A are being cut the valve plunger I33 is positioned to the left as shown in Figure 12, whereby the annular groove I33 connects fluid pressure from the line 3": to the line I33 connected to each of the table indexing cylinders 34 through the lines I334: so as to move and hold the indexing pistons 33 in their left hand position, Figures 6 and 12. Discharge from cylinders 34 passes out through the lines I40a into the line I40 which at this time is connected through the annular groove I in the valve plunger I35 to the drain line III for return to the reservoir 30.

When the plunger I35 of the control valve 1 34 is moved in the opposite direction, to the right, Figure 12, fluid pressure from the line 3lb will then be connected through the annular groove I H to the line I40 and through the lines' I404: to the cylinders 34 so as to move the plungers 33 to the right and thereby rotate or index the work and pattern fixtures in a clockwise direction to bring the slots of group B into position for machining. Fluid at this time will be discharged from the cylinders 34 through the lines I39a into the line I33 which now is connected through the annular groove I31 in the valve plunger I35 to the drain line III for return to the reservoir 30.

The movement )of the valve plunger I33 for indexing the fixtures to the group A position is accomplished by a cam actuating the plunger I42 of the group A indexing pilot valve I43 to the position shown in Figure 12, which connects fluid pressure from the pump 88 through lines 3I and Me, annular groove I44 of the valve plunger I42 and line I45 to the pressure chamber I33 in the control valve I34. When it is desired to index the fixtures clockwise for positioning the work for machining group B slots, the valve plunger I42 is allowed to move down by its cam wherein line I45 is connected through the annular groove I44tothe drain line III, while the group B indexing control valve I41 has its plunger I43 cam actuated to a position that fluid pressure from the line I and lid, is connected through the annular groove I43 of the valve plunger I43 to the line I43 which is connected to the pressure chamber I31 of the control valve I34 so as to move the plunger I35 to the right. Thus, by appropriately actuating the valve plungers I42 and I43, the plunger I33 of 8 the spindle indexing valve I34 may be hydraulicalLv actuated to one position or the other 30 as to effect the indexing of the fixtures for presenting group A or group B slots into the cutting position.

Fluid pressure maintained behind the plungers 33 for holding the fixtures in indexed positions is also utilized to operate the fixtures 1' on the work platens 21. For instance, the fluid pressure in the line I33 passes through a check valve I3I into a line I32 which is appropriately connected to the fixture clamping control valves I33 so that these valves may be operated to connect fluid pressure from the line I32 through the annular groove I34 of each valve I33 to an appropriate supply'line I33 connected to the fixtures to thereby clamp the work W. When the fixtures have been indexed in the opposite direction by application of the fluid pressure through the line I40, the fixtures F are still supplied with fluid pressure through a check valve I33 and the line I31. Thus, fluid pressure maintaining the work fixtures indexed in either direction also maintains the work properly gripped on the fixtures.

Means are provided to prevent feeding of the table unless all of the fixtures have fully indexed in either direction. This arrangement comprises means to maintain the solenoid I04 deenergized until the dogs 44 are in contact with the respective abutment blocks 33 or 40, Figure 6. This is accomplished by providing the dogs 44 with a projecting dog point 44a, Figure 3, which engages a push rod I33 carried in the support 3| which in turn engages a plunger I33 of serially connected shutofl! valves I33. when the valve plungers I33 are depressed against the compression springs I" a continuous connection of fluid pressure from the line I33 through the check valve I3I and the lines I32 and I33 will be established to the line I34. Pressure in the line I64 is connected to a pressure plunger I33 which actuates a limit switch I33 and through appropriate electric control means maintains the solenoid I04 energized, while if the dog is not in proper position, the solenoid will be deenergized.

Similarly, when the fixtures are indexed in a clockwise direction for machining the slots of group B, a second group of serially connected valves I31 will be similarly actuated by push rod I31a engaging plunger I31b as shown in Figure 5, to eifect connection of fluid pressure from a line I33 and the interconnecting lines I33 between these valves to a line I10 connected to the pressure plunger 'I1I associated with the limit switch I12 so that when all of the spindles are indexed to proper position for cutting the slots of group B, pressure will be applied to the pressure plunger Hi to actuate a limit switch I12, causing energization of the feed solenoid I04. In the event, however, that one or more of the spindles have not fully indexed so as to bring the dog point 44a to a position to engage the push rod "la and open one of the valves I31, the limit switch I12 will not be actuated, thereby preventing operation of the forward feeding movement of the work table 22. There has thus been provided an interlock arrangement for a series of indexable work and pattern supports which automatically prevents feeding movement of the work table carrying said supports in the event one or more of the supports have not been fully indexed:

The movement of the cross slide is hydraulically controlled by the tracer valve 33 which has an axially shiftable tracer valve plunger I23 which has a central neutral tracing position as previ- 9 ously stated. When the tracer valve plunger I28 is overdefiected, that is, moved beyond its neutral position towards the top of the sheet as viewed in Figure 12 the cross slide will move backward has annular grooves I80 and I8I which connect line I18 to a line I82 and line I11 to line I83. The line I83 is connected to the chamber I84 of the cylinder 50 while the line I82 is connected to the chamber I88 through check valve 200. A

branch line leads to a variable feed control valve IBM and through a line I85 to a pressure reducing valve I88 which, in turn, is then connected through a line I81 directly to the chamber I88 of the cylinder 50.

At the start of the cycle with the cross slide retracted and the tracer free, the spring 20I will move the tracer valve to its undeflected psition, whereby fluid pressure will flow from line 9If through the annular groove I15, line I11, annular groove I80 and line I93 to chamber I84 of the cross feed cylinder 50 which will cause advance of the cross slide. The fluid discharging from the other end of the cylinder will close check valve 200 and thus be forced through the line I81, valve I96, feed control valve I 84a. line I82, annular groove l8i of the valve I19, line I18, and annular groove I14 to the drain line III. As the forward movement of the slide takes place the plunger N9 of the valve I84a fixed on the base of the machine is actuated by a cam I90 carried on the cross slide 49 to throttle the discharge of a,sss,ees

this pressure through an annular groove 204 to the line 208 connected to the pressure chamber 201 to hold the valve plunger I19 of the stop valve I18 in the position shown in Figure 12. Discharge from the chamber 2I0 passes through line 208, and annular groove 209 of valve plunger 208 to the drain line I I I.

When the solenoid 202 is energized, its valve plunger 208 is so moved that pressure from the line 9| then passes through the annular groove 209 and the line 208 into the pressure chamber 2I0 of the valve I18 to thereby move its plunger I19 so as to block oil the lines I82 and I88 and thereby arrcst movement of the cross slide. Discharge at this time from the pressure chamber 201 of the valve I18 passes out through the line 208 through the annular groove 204 into the drain line II I for return to the reservoir 90.

The spindle carrier actuating cylinder 58 for the cutter spindle carrier is controlled by means of a servo-valve 2I I, Figure 12, which is carried on the cross slide 49 directly above the spindle carrier 55 as indicated in Figure 1. This valve has an axially movable plunger 2I2 having a downwardly extending sleeve portion 2I3, the end of which engages the steps 2 I4 formed on an index positioning drum 2 I 5 which is journaled on I a suitable shaft 2I8 in a bracket 2I1, Figure 4,

fluid through the line I81 and thereby restrict or decrease the rate of feed as the cutters approach their forward working position. At the same time, the tracer disc 10 will engage the pattern and move the tracer valve back to its neutral position and stop the feed.

Means have been provided for automatically overdeflecting the tracer valve plunger I29 to effect retraction of the cross slide as at the end of a cycle comprising a slide control valve I9I having a plunger I92 which may be actuated through a suitable bell crank lever I93 by a pair.

which actuatesthe tracer valve plunger I 29 a through a suitable lever I99 so as to move the plunger to overdeflected condition. When the solenoid I95 is energized,- however, pressure from the line Big is cut off from the pressure plunger I98 which is then connected to the drain line I I I so that the tracer valve plunger I 29 under the influence of the compression spring 20I will move to its unclefiected condition and thereby effect a forward movement of the cross slide.

The cross slide movement may be automatically stopped as at the point 11 in Figure '7 by downwardly shifting the plunger I19 of the cross slide blocking valve I18. This is accomplished by energizing the solenoid 202 of the pilot control valve 203. This valve 203 receives a supply of fluid pressure from the line 9| and when the solenoid 202 is deenergized the valve normally connects rigidly fixed to the spindle carrier 55. The plunger and sleeve have an axial bore through which passes a switch operating rod 2I3a, to be described later. This drum 2I5 is adapted to be driven through suitable gearing comprising a bevel gear 2I8 fixed on the shaft 2 I8 and a mating bevel gear 2 I9 appropriately journaled in the bracket 2I1 and driven through a universal joint 220, Figure 1, a drive shaft HI, and a universal joint 222 connected to the indexing control shaft 223 journals-d in suitable bearings in the spindle carrier 55.

Vertical indexing movement of the spindle carrier 55 is controlled by a solenoid operated indexing valve 224 having a plunger 225 urged in one direction by a compression spring 228 and in the opposite direction by energizing the solenoid 221. Normally, when the solenoid 221 is deenergized, pressure supply from the line 9Ih is blocked at the valve 225 as shown'ingFigure 12. When the solenoid 221 is energized to efizct indexing, fluid pressure is connected from the line 9Ih through the annular groove 228 of the valve plunger 225,

and line 229 tojchamber 230 of the detent plunger cylinder 23I causing withdrawal of detznt plunger 232 from the detent wheel 233 fixed on the indexing shaft 223. This detent plunger 232 is thus ,moved back against the resistance of a compression spring 234 in the chamber 235 of cylinder 23 I, fluid being discharged from this chamber out through a line 238 through the annular groove 231 of the plunger 238 of a. control valve 239 whcreitenters the drain line for return to the reservoir 90.

When the detent plunger232 is fully withdrawn, fluid pressure from the line 229 is connected to the line 240 and is thus transmitted to the pressure chamber 24I behind the ratchet plunger 242, this plunger having a suitable pawl adaptzd to successively engage the ratchet teeth 243 formed in the ratchet wheel 244 fixed on the indexing shaft 223. As pressure builds up in the chamber 24I the ratchet plunger 242 rotates the ratchet wheel 243 and shaft 223 one indexed position to bring the next step on the indexing drum 2I5 beneath the rod 2| 3a and sleeve 2I3 of the servo-control valve 2i I. When the plunger 242 accuses 22 completes its movement, the plunger 236 of the control valve 233 is moved so that fluid pressure from line 3Ii connected to line 236 causes pressure to be applied in the chamber 235 to rapidly move the locking plunger 222 back into engagement with the detent disc 233. I

As soon as the indexing has been completed and the solenoid 221 of the control valve 224 is deenergized, the valve plunger 225 will assume the position shown in Figure 12 wherein the chamber 236 of the detent plunger cylinder 23i is connected through the line 226 to the drain line i5!) so that compression spring 245 may automatically return the ratchet plunger 242, the fluid being discharged from the pressure chamber 2 through the line 246 and the check valve 246 to the drain line i515. Thus, whenever solenoid 221 is energized, the shaft 223 of the indexing mechanism is indexed one position and when this solenoid is deenergiaed the apparatus is reset for another indexing movement.

At the beginning of a machining cycle with the spindle carrier 55 in its lowest indexed position indicated at 241 in Figures 8 and 10, the sleeve 2I3 of the servo-valve plunger and the rod 2l3a will be on the highest step tide of the indexing drum 2&5, and as the indexing takes place the drum will be rotated intermittently and the sleeve 2I3 will successively drop to the next lower step until the ai bottom step 2I4b is reached. In this particular arrangement the inflexing drum M5 is provided with two series of steps from the points 2i4o to 2066 for group A and 2I4c to 2i4d for group 18 slots so that the sleeve 2I3 will pass through two complete intermittent dropping cycles for one complete revolution of the drum 2I5.

With the servo-valve plunger sleeve 2 is on the step 2I4a, indexing oi the d 2 it one position will momentarily cause the servo-valve plunger 2I2 to dro whereby pressure from the line M will be connected through the annular groove 241 and line 246 to the lower chamber 266 of cylinder 56 to cause the carrier to be raised to the next indexed position. The index drum, being mounted on the carrier, will move upward with it, thereby moving sleeve 283 and servo=valve plunger 2 I2 to its neutral position, thus cutting ofl flow from the pressure line M to the cylinder 56. Fluid is discharged from the chamber 266 of the cylinder 56 through the line 25H, the annular groove 252 of the servo-valve plunger 202 into the drain line II I. Thus, as the indexing shaft 233 is indexed by appropriately energizing solenoid 221 01' the indexing valve 224, the servo-valve 2 will each time be momentarily unbalanced until the spindle carrier has moved up to the next desired index position, this, process continuing until all of the steps 2I4 on the drum 255 have been passedover and the sleeve N3 of the servo-valve finally arrives at the last step 2 I 46, this condition occurring after a hall revolution of the drum 2I5 for group A slots and being repeated during the second half revolution of the drum tor the slots 01 group B. 7

As the last index position M41 or 2 I 4:1 is reached, a cam 253, Figure 12, fixed on the indexing shaft 223, actuates the plunger 254 of a con- ,trol valve 255 so as to connect pressure from the 12 I the line "I which communicates with the upper chamber 256 of the cylinder 56 to thereby rapidly move the cutter spindle carrier downwardly. At this time fluid is discharged from the lower chamber 243 of the cylinder 56 out through the line 246, annular groove 241 into the interconnecting line 253 which is at all times connected to the drain line I II. Thus, after the indexing movement for the last slot and a further final indexing of the shaft 223 takes place, the cam 253 actuates the valve plunger 254 to eii'ect the downward return of the cutter spindle carrier to its starting position 241 indicated in Figures 8 and 10.

With the fluid pressure pumps 86 and 38 operating and delivering fluid pressure to the lines 3i and I06, Figure 12, the work cycle 01 the machine is started by operating the manual push button switch 266, Figure 11. to complete a circuit from lead 26I through the switch 260, line 262, and relay 263 to power main 264. The relay closes contacts 263a in a circuit 265 to energize relay 266 which controls operation of the solenoid I35 which causes shifting of the pilot valve plunger I32 shown in Figure 12 into a position to release the tracer valve 69 and thus cause inward movement of the cross slide 49. The circuit 265 is completed from line 26I through limit switch contacts 261a, 266a, I66, contacts 263a and relay 266 to power main 264.

It will be noted that in the circuit 265 the pressure limit switches I66 and I12 operated by the' work fixture are connected in parallel in this starting circuit so that one or the other must be closed in order to start the machine, and it is assumed that switch I66 is so closed.

Since the contacts 263a will open upon release of the push button, the relay 266 latches itself in through a latching circuit comprising line 263, latching relay contacts 266a of relay 266, line 216, normally closed switch contacts 21I a, line 212 to closed limit switch contacts 268a. The result is forward movement of the crossslide 49 from its starting position 1I, Figure '7, along the line 12. Attention is invited to the fact that a dog 213 on the table, as shown in Figure 1, is holding the switch 268 closed as shown in Figure 11 when the table is in its starting position. It is also to be noted that the step 2| 4a on the turret 2I5 not only suppors the sleeve 2 I3 of the servo-valve but also the operating rod 2I3a for switch 261 and in such position as to close the contacts 261a as shown in Figures 4A and 11. The rod and sleeve, although telescoping one another, are separate independent parts. This positions the cutters and tracer disc vertically i'or machining the first slot in group A, the servo-valve being in a position to hold the piston 51 against movement.

When the cross slide 49 is in its starting position 1|, a, dog 214 holds limit switch 215 open as shown in Figures 2 and 11.

As soon as the cross slide advances, the dog 214 moves of! of limit switch 215 which closes and completes a circuit from power main 26I through line 216 to the spindle motors-64 which start rotation of the cutters.

Also in the starting position of the machine, the index shaft 223 positions a cam 211 fixed on the shaft to hold the plunger I 42 of the group A work and pattern spindle indexing control valve I43 in the position shown in Figure 12 to apply fluid pressure to one end of valve I34 and thus connect pressure to the cylinders 34 to actuate the index plungers 33 in a direction to hold the 11 51 21 and 28 in position for machining the slots of group A, thus closing interlock switch I99. A second cam 219 also fixed on the shaft 2" holds the plunger I 49 of the group B work and pattern spindle indexing control valve I41 in p sition to connect the left hand end of valve I94 to reservoir. Fluid from cylinders 24 discharges through line I48, and valve I34 .to reservoir through line I I I.

The cross slide 49 advances along theline 12 in Figure 7 to the position 14 at which time a dog 219 on the cross slide engages the limit switch 21I which, as shown in Figure 11, opens contacts 21Ia to break the circuit to the cross slide solenoid I99 and closes a circuit through contacts 21") and line 284 to relay "I which causes actuation of the table pilot valve solenoid I94. This a relay carries contacts Illa which close to com plete a latching circuit throu h line 282, closed contacts 289a of limit switch 289, line 294, closed contacts 299 of limit switch 299 and line 281 to the power main 29L It is necessary to set up this latching circuit because as soon as the table starts to feed due to the operation of solenoid I94, the dog 219 carried by the table moves out of engagement with the limit switch 298 opening contacts 289a which breaks the circuit to limit switch 2'", and closes contacts 299?) which is ineffective at this time but which is in acircuit to eventually cause operation of the rapid traverse solenoid I99. 9

It will be noted that the table will not start feeding movement to the left. in spite of operation of solenoid I94 untilthe tracer disc 19 engages the pattern and moves the tracer valve plunger back to its normal tracing position which establishes interconnection between table teed lines I9I and I92. Discharge from the table cylinder 23 is then controlled by the feed approach throttle valves III and I29 so that initially the table feeds slowly until the cutters have engaged the work, and then ultimately the table increases to the full desired i'eed rate to complete the machining of the slots.

When the work table 22 has completed cutting the first slot in group A and the cutters and tracer reach the point 18 on the. diagram in Figure 7, a dog 288 on the table actuates limit switch 283 to open contacts 283a, thereby breaking the latching circuit to table feed solenoid I94 which permits table pilot valve ifll to automatically centralize and thereby stopthe table feed; and closes contacts 299b which completesa circuit from power main 26I through line 281, closed contacts 295, line 284, closed contacts 293b, line m to relay zen which causes operation of sole noid I 94 and shifting of cross slide pilot valve I9l. This causes withdrawal of the tracer plunger I29 away from the pattern array to effect withdrawal of the cross slide.

As the cross slide 49 moves backward from the position 19, a dog 29I on the cross slide depresses limit switch 292 which, as shown in Figure 11, completes a circuit from power main 26I through limit switch 292 closed contacts 293a of limit switch 293 to index relay 294. This relay controls operation of the turret index control solenoid 221. Operation of this relay closes contacts 295 in a branch circuit 298 supplied through limit switch 292, thereby completing a circuit through normally closed contacts 291a of a relay 291 to relay 298 which governs the operation of the cross slide blocking valve solenoid 282. The cross slide is thus stopped at the point I1 and assumes the hydraulic'indexing of the turret III takes place.

The turret 2I9 rotates in a direction as viewed in Figure 12 to move the step 2I4a to the right whereby the sleeve 2I3 and connected servovalve 2I2 drop to cause an upward'indexing of the spindle carrier to a position to cut the next slot in group A At the same time, the rod. 2Ila drops to permit the limit switch 261 in Figure 11 to open contacts 261a and close 261b, completing a circuit through a timer relay 299. Operation of this relay closes its contacts 299a which are in a circuit with contacts 281a oi the limit switch 261. Thus, when the indexing operation of the spindle carrier 55 is completed, the next step on the turret will raise the rod 2Ila and close the switch 291a and complete a circuit through closed contacts 299a, closed contacts 299b, line 399, fixture closed limit switch contacts "9a, and line 3III to rapid traverse relay 202. This relay controls the operation of the table rapid traverse solenoid I whereby the valve I92 is now shifted to the right to eflect rapid traverse return of the table. At the same time the relay 302 closes contacts 992a to latch itself in across the timer relay contacts 299a, because these contacts are due to automatically open after a time delay due to the breaking of the circuit to the timer relay 299 by the opening of contacts 291b.

When the work table 22 completes its rapid return movement to the starting position with the cutters and tracer disc in a position corresponding to point 18 in Figure 7, the dog 212 on the table actuates the limit switch 268 which breaks the circuit to line 398 and relay 292, thereby deenergizing the solenoid I95 and again permitting the pilot valve IM to automatically assume its neutral position, thus centralizing valve 92 to arrest movement of the work table. Attention is invited to the fact that when the cross slide moved out of its cutting position it released the limit switch 21I which had been held closed by dog 219 during the cutting, thereby closing contacts 21ia, and that another dog became effective at position 11 to close the limit switch 292', completing the circuit to the turret index control relay 294, and that the parts have remained in this position during the rapid traverse return of the table. The index relay 294 at the time that it was operated closed a pair of contacts 294a to complete a circuit from the closed contacts 21Ia of limit switch 21I,'lines 210 and 269 to the control relay 266 for the cross slide control solenoid I95. Thus, when the limit switch 288 was actuated by the table dog 213 at the end of the rapid traverse return of the table it completed a circuit from main 26I through closed contact 261a of limit switch 291 and closed contacts 298a of limit switch 298 and line 212 to the closed contacts 21Ia of limit switch 21I whereby the solenoid I95 is again energized. Simultaneously, the operation of relay 268 opened the normally closed contacts 269b, releasing the blocking valve relay 298 whereby the blocking valve opens to start a slide released limit switch 292, thereby breaks ing the circuit to the relays 294 and 298 for the index solenoid 221 and block valve solenoid 292 respectively. Since the relay 294 becomes del8 energized its contact 2840 open in the circuit to the cross slide relay 288, but as soon as this relay was energized it latched itselt in through the closing of contacts 288a connected in parallel across the contacts 234a.

The above-described cycle of events repeats until the last slot in group A has been completed. 'However, as the indexing shaft 223 rotates to index the spindle carrier from the next to lastslot to the last slot to be cut in group A, a dog on the cross slide actuates limit switch 282 as before to cause operation of the turret index relay 2" and the blocking valve relay 288. The blocking valve relay immediately latches itself in by clos ing contacts 298a so that it is unaffected by the rest of the circuit. When the indexible shaft 223 completes this particular index rotation, a cam 303 fixed on the indexing shaft actuates limit switch 293, opening contacts 283a and closing contacts 29311 which completes a circuit from power main 26I through line 304 to control relay 281. Operation of relay 291 closes its normally open contacts 291!) and opens its normally closed contacts 2911:, thereby completing a circuit around the recently opened contacts 288a of limit switch 293 but unaflecting the circuit to the blocking valve control relay 298 because this was latched in through the closing of contacts 298a.

Although the circuit to control relay 234 was momentarilybroken, it happens so quickly that it is impossible to effect a second indexing through the hydraulic indexing circuit.

The indexing operation at this time will con tinue in the usual manner and the cross slide will eventually advance to cut the last slot in group A, The object of operating the limit switch 293 at this time is to set up the circuit to prevent operation of the blocking valve upon the final retraction of the cross slide so that the cross slide will not be stopped by the blocking valve but will return to itsextreme outward position. This is accomplished by opening the normally closed contacts 291a so that upon closing oi the contacts 295 during the next return movement of the cross slide a circuit will not be completed to the block ing valve control relay 298, and the cross slide will continue to its extreme outward position. It will thus be seen that upon completion of the last slot in group A that the circuit is so con ditioned by the closing of contacts am that during the return movement of the cross slide the limit switch 282 may close the circuit to the turret index relay 294 a sumcient length of time to eflect an indexing of the turret without operating the blocking valve.

Due to the fact that the surface tiib on the index drum M5 is provided with two steps of equal height at this point the shaft 223 indexes another position after cutting the last slot in group A, without moving the servo-valve or oper ating the switch 281. The indexing of the shaft 223 at this time, however, causes the cam 253 fixed on the shaft to actuate the valve plunger 254 on the latch-up va ve 255 for the servo=valve 2H so as to shift the servo-valve plunger 2I2 upward independent of rod H311 to cause return down ward movement of the spindle carrier and the turret drum 2I5 carried thereby. As soon as the turret 2 I5 moves downward, the limit switch operating rod 2I3a is free to drop and thereby open the limit switch 26V, or in other words open the contacts 281:: and close the contacts 26th.

This will cause operation of the timer relay 2%, closing contacts 289a, but the circuit will still be open at the limit switch 268 because the table was i8 has not yet returned, the tracer and cutter being in the position indicated by the point 13 in Figure 7. Another cam 388 is simultaneously indexed by the shaft 223 at this time to close limit switch 388 to maintain thecircuit to the spindle motors 84 because of the opening of limit switch 218 by dog 214 due to the cm slide returning to its extreme outward position.

' circuit 309 to a relay 3I0. The operation of this relay c oses contacts 3I8a to complete a branch circuit 3 to index relay 282. Thus, downward movement of the spindle carrier effects another indexing operation of the turret 2I5 while'the cross slide is still back. This brings the highest step 2I4c of the indexing drum 2I5 beneath the rod 2I3a of the limit switch 281 but the rod is still hanging free. This same index movement of the shaft 223 causes the cam 253 to release the pilot valve 255, whereby the spring-actuated bell crank 258 may return the servo-valve to such a position that it will cause the spinde carrier to move upward and thus eflect engagement of the highest step 2Ilc on the indexing drum 2I8 with the rod H311 and the servo-valve sleeve 2I3 to position the cutters and tracer vertically for cutting the first slot of group B. By this same indexing movement acam M2 on the shaft 223 actuates the limit switch 238 opening contacts 285 and closing contacts 288a, thereby transferring the circuit 281 from line 288 to line 3I3. The circuit 3 I 3 leads to the limit switch 3 which is mounted on the front of the bed as shown in Figure 1 for controllingthe new length of table movement in cutting the slots of group B.

i In addition, the indexing movement of the shaft 223 causes cam 211 to actuate va ve plunger I42 of the work and pattern fixture indexing valve I83 while at the same time cam 218 actuates valve plunger I46 of the fixture indexing valve I" to thus shift the work fixture indexing control valve I34 to effect clockwise indexing of the work and pattern fixtures to position the slots of group B oppos te the cutters. When all of the fixtures 21 and 28 have rotated to their full indexed position and shifted all of the valves I81 in the manner previously, described, the pressure switch I12 will close and switch I88 will open. The contacts I124: of switch I12, it will be noted, are in the circuit with the tabe rapid traverse control relay 302 whereby if all of the work fixtures are not fully indexed this relay will not be operated.

It will thus be noted that this last indexing movement of the shaft 223 was for the purpose of positioning the parts to start the cutting of the slots in group B and caused indexing of the work fixtures with the resultant c osing of thednterlock limit switch I12, transfer of the circuit from table limit switch 283 to table limit switch 3| 4, and upward indexing of the s indle carriers which caused operation of limit switch 261- by opening contacts 281D and closing contacts 251a. Since the timer relay had previously closed contacts 2919a and since the limit switch .263 is still re eased. closing contacts 26%. a circuit is completed through line 300, l mit switch contacts il2o to the table rapid traverse control relay 17 302 which is now actuated to cause operation of solenoid I and thereby through the hydraulic 1caiatmluit to eifect rapid return movement of the This movement is stopped when the dog 213 on the table actuates limit switch 268 and opens contacts 268b, breaking the circuit so as to release solenoid 105 and permit the pivot valve 101 to automatically centralize and lock the table in a stop position.

It is to be noted that when the limit switch 293 was actuated to condition the circuit for preventing operation of the blocking valve after all of the slots in group A were cut, that the relay 291, which was energized at that time, closed a pair of contacts 2910 to close a circuit from the power main 261 through a pair of normally closed contacts 2660 of relay 266 to a relay 315. This relay carries a pair of contacts 315a which close to latch the relay in around contacts 2910. The relay 315 also closes another pair of contacts 315!) in a circuit 316 containing contacts 112b, normally closed contacts 291d and 315!) to relay 311.

The resulting operation is that the limit switch 293 was released by its cam during the last index operation which positioned, the parts for cutting slots in group B, thus opening contacts 2931) and deener-gizing relay'291. This caused the contacts 2910 to open in the circuit to relay 315 but this relay was latched in by its closed contacts 315a and since the cross slide is still in a return position the relay 266 is deenergized so that the normal closed contacts 2660 are still closed. In the circuit 316 contacts 3151) are closed due to the energization of relay 315, the contacts 291d are closed due to the deenergization of relay 291, and the contacts 1121) are closed due to the completion of the indexing of the work fixtures to a position for cutting the slots of group B. Thus,- relay 311 is energized.

This relay carries a pair of contacts 311a which are thus closed to complete a circuit from line 2111 to line 269 and thereby to cross slide relay 266. The above-described operation, whereby the contacts 311a. were closed, occurred before the table started its return rapid traverse movement whereby upon completion of its return movement and operation of limit switch 268 by dog 213 a circuit was completed through closed contacts 261a of limit switch 261, closed contacts 268a of limit switch 268, line 212, closed contacts 211a of limit switch 211, line 210, closed contacts 311a, line 269 to cross slide relay 266. Thus, the completion of the return movement of the table after the cutting of slots in group A caused deenergization of the rapid traverse solenoid 105 and the completion of the circuit to the cross slide solenoid 195 whereby the cross slide starts to move in to cut the first slot in group B. The energization of the relay 266 to cause operation of the solenoid 195 immediately closed contacts 266a whereby the relay 266 became latched As soon as relay 266 was energized it opened contacts 2660 in the circuit of solenoid 315 whereby the relay became deenergized and opened contacts 315:: in circuit of relay 311, thereby deener-gizing that relay and opening contacts 311a in the circuit to the cross slide solenoid 266. Thus, these circuits are released and ready for the next cycle.

The cross slide is now in position 80 indicated on the diagram in Figure 9, and the work fixtures are indexed to a position to present th group B slots to the cutters. The cross slide then moves forward along the line 81m to the position 81, and the table is automatically caused to feed in the direction of arrow 15b. In this portion of the cycle, as previously mentioned, the length of movement of the table is controlled by'the limit switch 314 which is operated by a separate dog 318 carried by the table. The limit switch 314 has a first pair of contacts 314a which are closed at the beginning of the cycle to establish a circuit through line 282 to the table feed control relay 281. When the feed movement is ended, the limit switch 314 is operated by the dog 318 to close contacts 314?; to complete a circuit to the cross slide relay 290 which functions in the same manner as before.

The remainder of the cutting cycle takes place as in the case of group A but with the limit switch 314 defining a shorter feed stroke for the work table 22. After the final slot is completed in group B and the spindle carrier 55 returns downward along the line 81, the limit switch 308 on the spindle carrier 55 is again operated by the dog 301 causing index of the shaft 223 to again bring the high step 21 111 in the group A series of steps on the indexing drum 215 into position under the sleeve 213 of the servo-valve 211. This indexing of the shaft 223 actuates valve 255 to release the servo-valve plunger 212 to allow the spindle carrier to move upward from the position 24111 to position 241, Figure 10, to bring the high step 214a into engagement with the rod 213 and thereby position the spindle carrier for cutting the first slot in group A and at the same time closed limit switch 261. The work fixtures would be indexed again back to the position for cutting slots A which would open interlock limit switch 112 and close interlock limit switch 166. Since the limit switch 112 is now released, its contacts 112!) will be open whereby the relay 311 will be deenergized, thus leaving its contacts 311a in the circuit to the cross slide relay 266 open whereby upon the last rapid traverse return of the table after cutting the slots in group B and indexing the fixtures fox-group A, the dog 213 in operating limit switch 268 and closing contacts 268a would not complete a circuit to the cross slide relay 266 whereby the machine would stop. It would then be necessary for the operator to push the button 260 to start the next cycle of the machine. It is also to be noted that when the cross slide returned to its extreme outer position after cutting the slots in group B, the limit switch 306 will not be closed by its cam so that the dog 214 in opening the limit switch 215 will stop operation of the spindle motors. The finished work pieces may now be removed from the fixtures and the machine reloaded with unfinished work pieces.

What is claimed is:

1. In a pattern controlled machine tool, a reciprocable work table, indexible work and pattern fixtures mounted on said table, a cutting tool spindle supported for lateral movement toward and from the index axis of the work fixtures, pattern controlled means including a tracer engageable with a pattern array mounted on the pattern fixture to control lateral movement of the tool spindle during a cutting operation, means for indexing said tool spindle axially to position the cutter successively in a series of predetermined cutting planes, and means responsive to movement of the tool spindle to the last cutting plane of a series to efiect indexing of the work and pattern fixtures.

2. Ina pattern controlled machine tool having 19 a reciprocable work table, power operable means for feeding the table in one direction and rapid traversing the table in a return direction, work and pattern fixtures indexibly journaled on said 3. In a pattern controlled milling machine havv ing a frame, a work table reciprocably mounted on said frame, power operable means for feeding the table in one direction and rapid traversing the table in the other direction, indexible work and pattern fixtures journaled on said work table, a cutting means supported for movement toward and from said work fixtures, tracer control means including a tracer for cooperating with pattern means on said pattern fixture to vary the relative movement between said cutting means and work fixture, means for indexing said cutting means to a plurality of predetermined cutting planes, means responsive to indexing of said cutting means to its last cutting plane to effect indexing of said work and pattern fixtures, and means responsive to said indexing movements to automatically vary the length of the table stroke.

4. In a pattern controlled milling machine having a frame; a work table reciprocably mounted on said frame, a plurality of work and pattern fixtures indexibly mounted on said work table, a rotatable cutter and tracer means associated with the respective fixtures for machining a series of profiled surfaces on the work carried by the work fixtures during movement of said work table, said pattern fixture carrying a series of patterns for controlling the contour of each surface to be cut, individual fiuid pressure operated means for indexing said fixtures to present new work surfaces and a new pattern array to said cutter and tracer means, and hydraulic control means effective to prevent operation of the machine during the indexing operation.

5. In a pattern controlled milling machine, a frame, a work table reciprocably mounted on said frame, a plurality of work and pattern fixtures indexibly journaled on said work table, a cross slide supported on said frame for movement normal to the direction of movement of said work table, a tool spindle carrier mounted on said cross slide for movement parallel to the index axes of said fixtures, tool spindles individual to each work fixture journaled on said carrier, a prime mover mounted 'on said carrier for rotating said tool spindles, tracer controlled means mounted on said carrier for operativeengagement with pattern means carried by the pattern fixture, means to oscillatably index said fixtures through a semi-circle, means to change the length of movement of the work table afterframe, awork table reciprocably mounted on said frame, a plurality of work and pattern fixtures indexibly journaled on said work table, a cross slide supported on said frame for movement table, a tool spindle carrier mounted on said cross slide for movement parallel to the index axes of said fixtures, tool spindles individual to each work fixture journaled on said carrier, a prime mover mounted on said carrier for rotating said tool spindles, tracer controlled means mounted on said carrier for operative engagement with pattern means carried by the pattern fixture, means to oscillatably index said fixtures through a semi-circle, means to change the length of movement of the work table after each indexing operation, means controlled by the work table to eflect retraction of the cross slide and indexing of the tool carrier after each cutting operation, and interlock means to prevent movement of the table and cross slide during indexing of said work and pattern fixtures.

7. In a pattern controlled milling machine having a reciprocable work table, a plurality of work and pattern fixtures indexibly joumaled on said work table, means for rotating and holding said fixtures in one of either indexible positions, a tool carrier supported for movement in two directions in a plane normal to the axis of the movement of the-work table, a tracer control means mounted on said carrier and engageable with a pattern on said pattern fixture for controlling the movement of said carrier toward and from the work and pattern fixtures, means responsive to engagement of the tracer with pattern means to initiate a feeding movement of the work table, means operable by movement of the work table for retracting the tool carrier at the end of a feeding stroke/to an intermediate position, means responsive to movement of the tool carrier to said intermediate position to effect indexing of the tool carrier parallel to the index axes of said fixtures to position the parts in a new cutting plane, means responsive to said indexing means to effect rapid return of the work table to its starting position, and trip means operated by the table upon its return to advance said carrier to a cutting positionto begin another cycle.

8. In a pattern controlled milling machine having a reciprocable work table, a plurality of work and pattern fixtures indexibly Journaled on said work table, means for rotating and holding said fixtures in one of either indexible positions, a tool carrier supported for movement in two directions in a plane normal to the axis of the movement of the work table. a tracer control means mounted on said carrier and engageable with a pattern on said. pattern fixture for controlling the movement of said carrier toward and from the work and pattern fixtures, means responsive to engagement of the tracer with pattern means to initiate a feeding movement of the work table, means operable by movement of the work table for retracting the tool carrier at the end of a feeding stroke to an intermediate position, means responsive to movement of the tool carrier to said intermediate position to effect indexing of the tool carrier parallel to the index axes of said fixtures to position the parts in a new cutting-plane, means responsive to said indexing means to effect rapid return of the work table to its starting position, trip means operated by the table upon its return to advance said carrier to a cutting position to begin another cycle, and means responsive to indexing of the tool carrier to the last of a series of predetermined positions to effect full withdrawal of the tool carrier and automatic indexing of said work and pattern fixtures.

normal to the direction of movement of said work 9. In a pattern controlled milling machine hav- 21 ing a reciprocable work table, a plurality of work and pattern fixtures indexibly journaled on said table, a tool spindle carrier supported for movement in two directions in a plane normal to the direction of movement of said table, a tracer control means carried by said carrier including a tracer engageable with pattern means on said pattern fixture for controlling a cutter carried by the tool spindle relative to the work during feeding movement of the table in one direction. means operated by engagement of the tracer with the pattern to initiate feeding movement of the work table, means controlled by the table to effect withdrawal of the tool carrier to an intermediate position at the end of the table feeding stroke, means responsive to movement of the tool carrier to its intermediate position to effect indexing of the tool spindle carrier in a direction parallel to the axes of the work and pattern fixtures, said indexing means causing return of the work table to a starting position, and trip means operated by the table upon return to its starting position to advance the tool carrier for a second cutting operation.

10. In a pattern controlled machine tool having a reciprocable slide for supporting a work piece and pattern means, and a tool support carrying a metal working tool and a tracer, the combination of power operable means for effecting advance and retractive movements of the tool support relative to a cutting position in which the tracer engages said pattern means, fluid operable means for reciprocating said slide, means responsive to engagement of the tracer with the pattern for connecting a source of pressure to said fluid operable means, trip operable means for stopping the movement of said slide, means simultaneously operable by said trip means to effect retraction of the tool support, and means actuated by the retracting support to efiect indexing of said tool support normal to its direction of advance and retraction.

11. In a pattern controlled machine tool having a work table, means to support a plurality of work pieces and pattern means on said work table, a cross slide movable normal to the direc- 4 tion of movement of the work table, a cutter spindle carried by said slide, a slotting cutter attached to said spindle for rotation in a plane parallel to the plane of said work table, a tracer carried by said cross slide for engagement with said pattern means upon advance of the cross slide, means responsive to engagement of the tracer for causing actuation of the work table and the cutting of a slot in the work piece to a depth determined by said pattern, trip operable means for stopping the table and effecting retraction of the cross slide, and means automatically operable by the retracting cross slide to effect indexing of the cutter to a second plane preparatory to cutting a second slot in the work.

12. In a pattern controlled machine tool having a reciprocating work support and a cross slide movable normally to the direction of move ment of the work support, the combination of a tracer mounted on said cross slide for-engagement with a pattern on the work support, a tracer controlled valve for controlling reciprocation oi the cross slide, power operable means for holding the tracer valve in a position to cause retraction of the cross slide, manually controlled power operable means for releasing said first-named power operable means, resiliently operable means for automatically positioning the tracer to cause advance of the cross slide, trip means operable by carried by the work support, the combination of transmission and control means for effecting relative movement between the supports to pattern control mill a series of profile surfaces in succession on one side of a work piece, means automatically responsive to completion of said series of surfaces to index the work and pattern array to present the opposite side of the work to the cutting means, and means responsive to completion of said indexing movement to cause said transmission and control means to pattern control mill a second series of profile surfaces on the opposite side of said work.

14. In a pattern controlled machine tool having a work support and a tool support, a tracer to cut a series of varying profile surfaces longitudinally of the work, means for determining when said series of surfaces have been out, said means causing indexing of the work and the presentation of a new series of pattern surfaces to the tracer, and means responsive to completion of said indexing to initiate operation of said automatic cycle control mechanism to mill a second series of profile surfaces on the work longitudinally thereof and in accordance with the new set of patterns.

15. In a pattern controlled machine tool having a work supporting table and a tool supporting slide movable normally thereto and a tracer carried by said slide for engagement with pattern means mounted onthe work table, the combination of power operable means for reciprocating said work table through a definite length of stroke, automatic cycle control mechanism for causing engagement of the tracer with the pattern means and reciprocation of the work table through a number of cycles to cut a plurality of profile surfaces on the work, means automatically operable for indexing said work after completion of said series to present another side of the work to said tool slide, and means automatically effective upon completion of said indexing movement to change the length of said table stroke and initiate operation of said cycle control mechanism to cuta second series of profiled surfaces on the work.

16. In a pattern controlled machine tool having a work support anda tool support and a tracer control mechanism mounted on said tool support for engagement with pattern means mounted on the work support, said mechanism including a tracer control valve, the combination of fluid operable means for retracting said tracer valve, electrically operated control means for said power operable means including a starting button for effecting release of said tracer valve, means responsive to release of the tracer valve for causing the tool slide to effect engagement of the tracer with the pattern means, power operable means for shifting the work support, electrical control means for starting and stopping said last-named power operable means, said electrical control means including a trip operable switch actuable by the advancing tool support for causing feeding of the work support upon engagement of the tracer with the pattern.

17. In a pattern controlled machine tool having a longitudinally reciprocable work support, a cross slide movable toward and from said support,

a tool carrier supporting a tool mounted on the cross slide for movement normal to the plane of movement of said support and cross slide, and an automatic tracer controlled mechanism mounted on the carrier for controlling movement or the cross slide, the combination of transmission and control mechanism for causing relative movement between the tool and work support to automatically machine a series of spaced profile work surfaces in a single automatic cycle including advance and retraction control relays operatively connected to the tracer, a push button for energizing said advance relay, feed and rapid traverse control relays for the work support, said advancing cross slide causing engagement of the tracer with a pattern means carried by the work support and simultaneously energizing said feed control relay whereby during subseqiuent feeding of the table the tracer will control'the shape of the profile surface, means operable by the work support for energizing said retraction control relay, means for indexing said carrier including an index control relay, means operable by the retracting cross slide to energize the index relay, a secondary circuit closed by said index relay for energizing a stop control relay which is operatively connected for stopping the cross slide, means responsive to completion or the indexing to energize said rapid traverse control relay and eiiect return of the.

work support, means actuated by the returning work support to energize said advance control relay and deenergize the stop control relay to cause a second advance of the cross slide, and means responsive to the advancing movement of the cross slide to deenergize the indexing relay whereby subsequent profiled surfaces will be machined in automatic succession.

18. In a pattern controlled machine tool having a longitudinally reciprocable work support, a cross slide movable toward and from the work support,

a tool carrier mounted on the cross slide for movement normal to the plane or movement of the table and cross slide and an automatic tracer control mechanism mounted on the carrier for controlling the cross slide, the combination of transmission and control mechanism for controlling movement of the parts including an advance and retraction controlrelay for the tracer, a manually controlled push button for energizing said advance relay to cause advance of the cross slide to move the tracer into engagement with a pattern means carried by the work support, means responsive to tracer engagement for subsequently controlling the position of the cross slide in accordance with said pattern means, power operable means for feeding the table including a feed control relay, and switch means in circuit with said feed control relay and operable by the cross slide simultaneously with engagement of the tracer with the pattern means for initiating a feeding movement of the work support.

19. In a pattern controlled machine tool having a power operated work support, a power operated tool slide carrying a tool support movable normal to the direction of movement of the work support and a tracer control mechanism carried by the tool slide including a tracer in engagement with pattern means on the Work support for controlling the movement of the cross slide, the combination of means for eflecting retraction of the cross slide at the end of a profiling operation including a control relay, switch means in circuit with said relay and operable by the table for energizing said relay, means operated by the relay for automatically retracting the tracer to effect retraction of the cross slide, a stop control interposed between the tracer and the power operable means for the cross slide, a control relay for said control, means to energize said last-named relay from the retracting cross slide to stop it in some intermediate position, and means simultaneously operable with said last-named means to eflect indexing of the tool support normal to the plane of movementof the table and cross slide to eflect automatic repositioning of the parts preparatory to machining a second profile surface on the work.

20.- In a pattern controlled machine tool having a longitudinally reciprocable work support, a cross slide movable toward and from the work support, a tool carrier mounted on the cross slide for indexing movement normal to the plane of movement of the table and cross slide, a cutting tool mounted on the carrier, and a tracer mounted on the carrier in engagement with pattern means on the work support for controlling a profilingoperation on the work during relative feeding movement between the work support and the cross slide, the combination of means for eifecting relative separation of the tracer and cutter relative to the pattern and work at the end of a feeding movement including a control relay operatively connected to effect retraction of the tracer, means operable by the work support for energizing said relay, an indexing mechanism for the tool carrier, means trip operable by the retracting cross slide to effect actuation of said indexing mechanism, a second control relay for the cross slide operatively connected for releasing said tracer, a control relay for causing rapid return movement of the table, a selector switch for said second relay and said rapid return re- .lay normally held in a position to connect said rapid traverse relay to a pilot switch in said indexing mechanism, said indexing mechanism being operable to open and close said pilot switch at the beginning and end of an index cycle,

means responsive to said opening and closing to complete a circuit from the pilot switch through said selector switch to the rapid traverse control relay to cause return movement of the table, and means carried by the table for operating said selector switch to stop the rapid traverse movement and energize said second relay to cause movement of'the tool and tracer toward the work support.

21. In a pattern controlled machine tool having a work support and a tool support and a tracer mechanism mounted on the tool support including a tracer for engaging a pattern on the work support and power operable means for feeding said supports, the combination of a tracer valve having a first position for causing feeding of the table, a second position for eflecting retraction of the cross slide and a third position for causing advance of the cross slide, fluid operable means for holding the tracer in its second position, electrically operable means including a starting button for releasing said fluid operable means, means normally urging the tracer to its third position, electrical trip means operable by the cross slide for potentially connecting a source of pressure to the table operating means, pattern means on the table for engaging and moving the tracer valve to its first posi- 

